Free flowing cyclotmmethylene



United States Patent --2,719'-,is"' Y t iLowlN sacrum" IMETHYLENE-TRINITRAMINE William Earle Schulz, Wenonah, N. 1., assignor to E. I.

du Pont de Nemours and Company, Wilmington, Del., a corporation ofDelaware No Drawing. Application March 23, 1953, Serial No. 344,194

3 Claims. (Cl. 260-248) The present invention relates to a method forimproving the flowing properties of cyclotrimethylenetrinitramine.

Cyclotrimethylenetrinitramine can be recovered from compositions inwhich it was mixed with trinitrotoluene, dinitrotoluene,mononitrotoluene, tetryl, and nitrocotton in the form of finely dividedparticles which pass a 50 mesh screen. This finely dividedcyclotrimethylenetrinitramine is not suitable for direct use in newexplosive compositions because of its poor flowing properties which makehandling difficult. Cyclotrimethylenetrinitramine of suitable particlesize can be obtained by recrystallization from a suitable solvent, butthis method of improving flowing properties involves considerableexpense. Moreover, the suitable solvents are highly flammable andintroduce a fire hazard which is particularly undesirable Whereexplosives are involved.

Mechanical mixing of calcium stearate with finely divided explosivecompounds is frequently used to produce compositions with improvedflowing properties. The calcium stearate has the added advantage ofacting as a desensitizer and a mold lubricant for most explosivecompounds. However, when mixed with finely dividedcyclotrimethylenetrinitramine, calcium stearate produces a flocculentsolid having only fair flowing properties.

An object of the present invention is to provide a process for improvingthe flowing properties of finely divided cyclotrimethylenetrinitramine.Another object of the present invention is to produce free-flowingcyclotrimethylenetrinitramine as a result of combination with awater-insoluble metallic salt of a high molecular weight fatty acid. Astill further object of this invention is to provide a process for theuniform intermingling of calcium stearate or a similar water-insolublemetallic salt of a high molecular weight fatty acid with finely dividedcyclotrimethylenetrinitramine, even when fractional percentages of thesalt are to be used with the explosive compound. Additional objects willbecome apparent as the invention is further described.

I have found that the foregoing objects may be accomplished by treatingthe cyclotrimethylenetrinitramine dispersed in a water slurry with awater-soluble salt of high molecular weight fatty acid, and thereafteradding to said water slurry a water-soluble salt of a metal which formsa water-insoluble metallic salt of said fatty acid.

In accordance with the process of this invention, finely divided,water-insoluble cyclotrimethylenetrinitramine is suspended in water withvigorous agitation and (LS-5% by weight of a water-soluble salt of asolid fatty acid having more than carbon atoms is added. To this aqueousslurry is added an excess of an aqueous solution of a salt of a metalcapable of forming a waterinsoluble salt with the fatty acid. Typicalsalts of this type are calcium chloride, magnesium chloride, zincchloride, lead chloride, and nickel chloride. The insoluble precipitatethus formed coats the larger grains of cyclotrimethylenetrinitramine andagglomerates the finer crystals during the precipitation.

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The dustiness usually produced when solid, waterinsoluble metallic saltsof fatty acids are mixed mechanicall y 'cfys't'alliiie entrees-Ins rsthu's avoided by the present riieth'oil of 'fo'r'ihing' the ih'solublecoating by t si ite iea .erslt emie. .ee s eng the presence of theexplosive chrr'ipound. Moreover, various amounts of the agent may beadded and a more intimate mixture obtained.

Ordinary hand soap and alkali metal salts of stearic acid may be used asthe source of the water-soluble coating agent. Solid fatty acids havingmore than 10 carbon atoms, especially those with an even number ofcarbon atoms, are preferred, and the fatty acids are added in amounts of0.55% by weight of the explosive compound.

Example 1 To a slurry of 500 parts of cyclotrimethylenetrinitramine and500 parts of warm water containing 15 parts (3% by weight) of dissolvedsoap, i. e. sodium stearate, was added, slowly, with constant agitation,12 parts of calcium chloride in parts of water. The solid obtained wasfiltered and dried. The treated cyclotrimethylenetrinitramine hadexcellent flowing properties.

Example 2 Two hundred parts of finely dividedcyclotrimethylenetrinitramine was mixed with 0.5% of a fatty alcoholsulfate in 500 parts of water. The fatty alcohol sulfate was added toreduce any static electricity on the cyclotrimethylenetrinitramine. Tenparts of soap, i. e. sodium stearate (5% by weight), was added and theslurry heated to 45 C. A solution of 5 parts of calcium chloride in 100parts of water was slowly added to the wellagitated slurry. The solidobtained was filtered and dried. The treatedcyclotrimethylenetrinitramine had excellent flowing properties.

Although the invention has been described in detail in the foregoingdescription, it will be apparent that many variations may be madewithout departing from the basic inventive concept. It is intended,therefore, to be limited only in accordance with the following claims:

I claim:

1. A process for producing cyclotrimethylenetrinitramine with improvedflowing properties comprising forming a slurry ofcyclotrimethylenetrinitramine particles in warm water, adding theretofrom 0.55% by weight of a water-soluble salt of a fatty acid andthereafter adding to said slurry an excess of an aqueous solution of awatersoluble salt of a metal which forms an insoluble salt with saidfatty acid.

2. A process for producing cyclotrimethylenetrinitramine with improvedflowing properties comprising forming a slurry of thecyclotrimethylenetrinitramine in warm water, adding to said slurry 0.55%by weight of a solution of potassium stearate, and thereafter adding tosaid slurry an excess of an aqueous solution of calcium chloride.

3. A process for producing cyclotrimethylenetrinitramine with improvedflowing properties, comprising forming a slurry of saidcyclotrimethylenetrinitramine in warm water; adding thereto 0.55% byweight of a soluble salt of a normally solid fatty acid of over 10carbon atoms; agitating the slurry; and thereafter adding to the slurry,with mixing, an aqueous solution of a salt of a metal selected from thegroup consisting of calcium, magnesium, zinc, lead and nickel. 5

References Cited in the file of thispatent UNITED STATES PATENTS1,728,307 Ripp Sept. 17, 1929 10 4 Nichol Mar. 8, 1932 Baldwin Feb. 6,1934 Meister Apr. 5, 1938 Lewis July 19, 1938 FOREIGN PATENTS GreatBritain Dec. 31, 1945 Great Britain 1946

1. A PROCESS FOR PRODUCING CYCLOTRIMETHYLENETRINITRAMINE WITH IMPROVEDFLOWING PROPERTIES COMPRISING FORMING A SLURRY OFCYCLOTRIMETHYLENETRINITRAMINE PARTICLES IN WARM WATER, ADDING THERETOFROM 0.5-5% BY WEIGHT OF A WATER-SOLUBLE SALT OF A FATTY ACID THEREAFTERADDING TO SAID SLURRY AN EXCESS OF AN AQUEOUS SOLUTION OF A WATERSOLUBLESALT OF A METAL WHICH FORMS AN INSOLUBLE SALT WITH SAID FATTY ACID.